Go Agent 1.0

Notes

Removed BetaToken from the Config structure.

Breaking Datastore change: datastore package contents moved to top level
newrelic package. datastore.MySQL has become newrelic.DatastoreMySQL.

Breaking Attributes change: attributes package contents moved to top
level newrelic package. attributes.ResponseCode has become
newrelic.AttributeResponseCode. Some attribute name constants have been
shortened.

Added "runtime.NumCPU" to the environment tab. Thanks sergeylanzman for the
contribution.